摘要
通过高能喷丸方法在工业纯钛表面制备了纳米表层,选择B-Ag40CuZnCdNi钎料对纳米化前后的纯钛进行了不同工艺的钎焊,借助微观组织分析和抗剪强度测定研究了表面自身纳米化对工业纯钛钎焊过程的影响。结果表明:用B-Ag40CuZnCdNi钎料钎焊工业纯钛时,表面自身纳米化预处理提高了母材表面的活性,促进了纯钛母材向液态钎料中的溶解,低温短时焊接时对接头性能提高有利,接头强度比未预处理时提高了13.8%。焊接温度超过650℃后,母材纳米表层的高活性使界面区的金属间化合物层增厚,接头性能反而下降;由于在焊接温度下元素的固态扩散不易进行,纳米化前处理对液态钎料中的元素向母材扩散的影响不明显;母材纳米化前处理后,钎焊时通过降低焊接温度和缩短保温时间,既可发挥纳米表层有益特性,同时避免不利影响。
A nanostructured layer was prepared on the surface of the commercially pure titanium by high-energy shot peening. Bra- zing with different process was carried on for the pure titanium before and after the high-energy shot peening, with B-Ag40CuZnCdNi as the filler metal. By microstructure observation and shear strength testing, the effects of the surface self-nanocrystallization on the bra- zing of commercial purity titanium were then investigated. The results showed that the surface activity of the base metal was improved and the dissolution of the titanium into the liquid filler metal was promoted on account of the surface self-nanocrystaUization pre-treat- ment as B-Ag40CuZnCdNi was used for filler metal. Low temperature and short holding time were beneficial to the performance of the welded joint, and the strength of the joint was increased by 13.8% compared with that of the as-treated joint. When welded above 650℃ , the strength of the joint decreased due to the thickening of the intermetallic compound layer in the interface zone, which was promoted by the high activity of the surface nanostructured layer of the base metal. Because of the difficulty in the solid-state diffusion at the welding temperature, the high-energy shot peening pre-treatment had limited effects on the diffusion of the filler metal. Lowering the temperature and shortening the holding time in the process of brazing after the pre-treating could not only promote the beneficial characteristics of surface nanostructured layer, but also avoid the detrimental effects.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2013年第5期732-737,共6页
Chinese Journal of Rare Metals
基金
辽宁省教育厅计划项目(L2012153)资助
关键词
工业纯钛
表面自身纳米化
钎焊
commercially pure titanium
surface self-nanocrystallization（SSNC）
brazing
